Optimizing a Protocol to Assess Immune Responses after SARS-CoV-2 Vaccination in Kidney-Transplanted Patients: In Vivo DTH Cutaneous Test as the Initial Screening Method

Previously, the delayed-type hypersensitivity (DTH) cutaneous test with the spike protein of SARS-CoV-2 has been shown to be a simple in vivo method to measure T-cell functionality after natural infection and in vaccinated individuals. Methods: Twenty-five kidney-transplanted recipients were immunized with two doses of the mRNA-based Pfizer–BioNTech COVID19 vaccine three weeks apart. Cell-immune response (CIR) was evaluated ten weeks later using an in vivo DTH skin test and in vitro with an interferon gamma release assay (IGRA). Humoral Immune Response (HIR) was determined by the measurement of specific IgG anti-S1 SARS-CoV-2. Results: Ten weeks after the second dose of the vaccine, 23 out of 25 transplanted patients had a positive DTH skin test, while in vitro CIR was considered positive in 20 patients. Unspecific stimulation was positive in all 25 patients, showing no T-cell defect. Seven out of twenty-five patients had a negative specific anti-spike IgG. CIR was positive in all immune-competent control patients. Conclusions: DTH is a useful, simple, and cheaper tool that can be used to assess cellular immune response, with an excellent correlation with the in vitro CIR. CIR assessment after vaccination in these immunocompromised patients is an excellent complement to HIR-based methods. This skin test could be used if classical in vitro methods cannot be applied.

The Beauty of Simplicity: Delayed-Type Hypersensitivity Reaction to Measure Cellular Immune Responses in RNA-SARS-Cov-2 Vaccinated Individuals

Background: Monitoring cellular immune responses elicited in vaccinated individuals is highly complicated. Methods: 28 individuals participated during the vaccination process with 12 BNT162b2 mRNA (Pfizer) vaccine. Specific anti-RBD IgG using a classic ELISA was performed in days 10 and 20 (after one dose of the vaccine) and on day 35 (after two vaccine doses) in serum samples of all participants. In parallel, DTH (delayed-type hypersensitivity) Skin Test using S protein was performed before (11/28) and after two doses (28/28) of the vaccine. Results: 6/28 individuals were considered positive for the specific anti-RBD IgG positive at day 10, whereas all 28 individuals were positive at day 20. Moreover, 28/28 individuals increased the OD ratios at day 36 (2 doses). DTH cutaneous test was performed on 11/28 participants at day 20 (1 dose) showing 8/11 a positive reaction at 12 h. DTH of all participants was performed on day 36 (2 doses), showing 28/28 positive reactions at 12 h. Conclusion: This report describes the first publication of the results obtained using an in vivo method, the classical DTH response to the Spike protein to assess T-cell immune responses in vaccinated individuals. This affordable and simple test would help to answer basic immunogenicity questions on large-scale population vaccine studies.

Allergy to Polyethilenglicole of Anti-SARS CoV2 Vaccine Recipient: A Case Report of Young Adult Recipient and the Management of Future Exposure to SARS-CoV2

The main contraindication to the anti-SARS CoV2 vaccine is an anaphylactic reaction to a vaccine component. The need to vaccinate allergic people who are at higher risk can be of public health interest and this report shows a case of an allergic reaction to PEG of a HCW who had received the first dose of anti-SARS CoV2 vaccine. For 5 h after the administration of the vaccine, she had the appearance of erythematous spots on the face and neck, and a feeling of a slurred mouth and hoarseness. In order to treat the event, she was administered 8 mg intravenous dexamethasone, 1 vial intravenous chlorphenamine maleate, 250 mL intravenous 0.9% NaCl, and conventional oxygen therapy (2 L/min) with complete resolution of the suspected adverse drug reaction. According to the contraindication to the cutaneous test for this patient, BAT was used for further investigations. The patient who suffered the adverse reaction to the COVID-19 vaccine and other five allergic patients who did not report any adverse reaction after the vaccination were tested. There was a significant activation of the vaccine-reactive patient’s basophils with 14.79 CD203chigh% at the concentration of 0.2 mg/mL, while other patients were negative. People who have a confirmed reaction to a vaccine component should undergo further investigation to discover other possible cross-reactions and select the right vaccine to immunize them.

Relationship between cancer and allergy.

e12018 Background: Many studies have suggested an inverse association between allergies and cancer, while others have found no relation between them, and still others have shown an increased risk of cancer in allergy patients. The conflicting findings from prior studies are partially due to the chosen research method, such as different definitions and measures for atopy, in addition to variations in the control of confusion factors, such as smoking and obesity. Objectives: Verify if there is a relation between certain types of cancer and allergies; investigate if there is a difference between individuals with and without cancer in relation to allergies. Methods: Case-control study carried out at the Alberto Cavalcanti Hospital of the Hospital Foundation of the State of Minas Gerais (FHEMIG), Brazil, from 2009 to 2011. The study included patients over 18 years of age, from both genders, who presented a diagnosis of cancer, as compared to healthy individuals, paired by gender and age. An anamnesis was gathered considering the medical history of the allergy, as diagnosed by a doctor, as well as the patients’ habits, associated illnesses, and the use of medications. For cancer patients, data concerning the tumor were recorded. Subsequently, an allergy percutaneous test was performed in each group to detect allergic hyperreactivity toward common inhalable, bacterial, and food antigens within our everyday environment. A blood sample was collected to quantitatively evaluate the eosinophils. Results: Both groups were paired according to interest variables, and eventual deviations were adjusted by means of multivariate analysis. Reports of allergies occurred in 30% of the patients in the cancer group, as compared to 53% in the control group (p<0.05), whereas in the cutaneous tests, a greater positivity occurred in the cancer group (69%) than in the control group (51%, p<0.05). No difference in the eosinophil values could be observed within the groups. Conclusions: Cancer patients present fewer allergies. By contrast, in cancer patients, positive cutaneous tests detected allergies which did not correspond to the clinical findings. Therefore, in cancer patients, the positive cutaneous test for allergies does not present a direct relation to the presence of clinically detectable allergies.